Posted
by
Soulskill
on Monday August 30, 2010 @07:10PM
from the resources-beyond-imagining dept.

An anonymous reader writes "Much fanfare has been made about manned missions to moons and planets, but little has been done about travel to the asteroids — until now. NASA is working on plans for a trip to the asteroids by 2025. This type of mission has great potential for positive economic return based on the fact that no effort has to be spent on getting in and out of a distant planet's gravity well. Yes, we should go to the planets, but we should master mining the asteroid belt for resources first because it is easiest. What do you think?"

“Peep it, I’ll break it down so you can absorb it (okay)You need to mind planets’ minerals and do it from orbit (yo)Some good advice, and you’re too much of a noob to ignore it (ay)You’ll get stranded with no fuel if you foolishly floor itI used to rock microphones rhyming in a stadium (okay)These days i launch probes mining for palladium (no doubt)”

Why? Because it's more exciting to launch a multi-billion dollar vehicle out billions of miles and engineer the safe return of some metallic dirt, than to drive over to similar dirt here on Earth and pick it up.

More or less, sure. Depending on the density, you could harpoon the asteroid with a retro-rocket and direct it back toward Earth for reentry. With low velocities, it could slam down in a desert area for safety. This would enable miners to excavate its resources with standard mining know-how that we have in place today.

Hmm, let's look at some numbers. In general, if it's coming in from outside our gravity well, it'll be hitting atmosphere at escape speed or a bit over. Or a whole lot over. But let's go with escape speed.

Why do you think that? I'm curious. Why not Mars orbit? It's not like the belt is actually that dense. I mean, you could blindly aim a spaceship through the belt, and as long as it can take collisions with pebble size objects, it'll almost certainly make it through unscathed. Most of its mass lies in few bodies. Putting a settlement on/around one of those would be just like putting one on any non-earth moon.My thinking is that the best place to set up self sufficient colonies independent of Earth is to star

"But I don't think it will be economically rewarding without our lifetime."

Of course not, given the silly desire to send humans early in the game.

There isn't a good reason not to send forty or fifty or whatever remote-manned missions first. Humans would be along for the ride merely for the adventure, which is nice but can wait. If we want to mine space, don't increase the cost by having miners onsite.

The dumbest idea in the movie Total Recall was that there would be any need for human miners on Mars in the

The dumbest idea in the movie Total Recall was that there would be any need for human miners on Mars in the first place.

Yeah, the giant alien-built pyramid which magically gave mars an atmosphere... that was WAY more realistic!

The plausibility of the scenario you complain about hinges entirely on the cost of transport at the time that the colonies were established. Given that middle-class people in the Total Recall Universe can apparently afford vacation travel to Mars, I'd say the idea of human miners is completely realistic. With the availability of such cheap travel, and the abundance of poverty on Earth, it makes perfect sense to ship off your poor and your criminals to slave away in martian mines, instead of sending billion-dollar machines.

If we were able to park our craft on an asteroid with a stable and well known trajectory it seems to me that we could hitch a free ride to the outer planets. Granted we would need some serious boosters to attain sufficient escape velocity but if such an asteroid could be found it would solve some problems. We have some seriously bright minds at NASA/JPL so I don't believe I'm the first person to think of this. Europa anyone?

To land on an asteroid, using technology remotely related to what we have now, it's going to have to match the velocity of the asteroid. Doing that negates any energy savings gained by the technique. Alternatively we could do a normal gravitational boost off of an asteroid, but the eccentric ones probably don't weight enough to help much. Or we could make super durable probes that can handle a tens of km/s collision with the asteroid, in which case we can then get our cheap ride to wherever it goes.

That's what I've been wondering. What metals, exactly, are more common there than down on earth, what's worth the price of getting there?
I'm having trouble imagining what could be worth the price tag...right now, at least, before we start running out of things.

Every metal that we currently mine in the earth's crust. They're all plentiful in asteroids, and rare on Earth. In fact, everything that we currently mine (copper, iron, zinc, platinum, gold, etc.) came from asteroid impacts. During the early formation of the planet, when it was still mostly liquid, all those elements moved to the core, leaving only things like calcium and silicon and carbon in the Earth's crust when it cooled. All the useful elements came from asteroid impacts after that.

Doesn't matter. They were a whole series of missions, not just one mission, and they were done with technology far behind today's (especially computer technology). After what we've learned there, and with modern technology, we should be able to pull off a single asteroid mission for a similar cost. The big unknowns are 1) how to deal with sending people that far away, especially in regards to radiation, though keeping the trip short should alleviate that concern, and 2) how to actually extract minerals from the asteroid and bring them back to earth in quantities sufficient to make it viable. Should we capture the asteroid (assuming a fairly small asteroid here) and bring it to earth orbit, or mine it where it is (allowing us to work with much larger asteroids)?

Obviously, the first mission probably won't be profitable, but we just have to figure out how to scale it up.

The radiation problem is a big one, and I think the public doesn't yet realize how big of a problem it is. I mean, flight attendants and pilots are exposed to about as much or more than someone working in a nuclear power plant, so shouldn't they be wearing radiation badges? http://iopscience.iop.org/0952-4746/21/1/003 [iop.org]
Now fast forward 50 yrs, with asteroid mining profits starting to take off. Will similar health risks get swept under the rug?

That's not really what I was getting at. If individual asteroids contain significant percentages of the total mined gold supply (a couple trillion), any successful asteroid mining is going to have a huge impact on the percieved value of all those metals (and just imagine a couple of capitalists in a friendly competition to bring back 50 times the amount of gold that is currently mined in a year, that would just barely show up over the decades it took to do it...).

You can say that there's billions of gallons of oil deposits, worth trillions of dollars, that are currently inaccessible due to technological limitations. That doesn't mean that it's worthless, it just means it's inaccessible.

In fact, everything that we currently mine (copper, iron, zinc, platinum, gold, etc.) came from asteroid impacts.

Only in the sense that Earth is basically built of asteroids in the first place. But in that limit, you're just advocating mining on Earth again, the nearest and most habitable such body.

all those elements moved to the core, leaving only things like calcium and silicon and carbon in the Earth's crust when it cooled. All the useful elements came from asteroid impacts after that.

Good lord, no. Certainly elements did tend to head to the core preferentially. Such siderophilic (iron-loving) elements are fairly rare in the Earth's upper layers. Others are still fairly common. Or at least common enough. Even iron, which lead the charge to the core during differentiation, is awfully common in the crust.

In fact, silicon (the second most abundant element in the crust) is only about ten times more common than iron, which is about as abundant as calcium (which you cite as being abundant). Aluminum is more abundant than calcium and is in fact only a few times less abundant than silicon. (Oxygen, incidentally, is the most common element in the crust, beating silicon out by a factor of a few.) In fact, most metals we're particularly attached to are about one-in-ten-thousandth as common as silicon. If you factor in the fact that they're usually found in clumps, that's a very cheerful thought.

By the way, if your theory of asteroid delivery were true, I'm pretty sure we wouldn't have very much metals to work with. The Earth's crust is tectonically recycled every several hundred million years (any given chunk has been subducted and recycled several times, more or less; we estimated this my first year of grad school, but I forget the numbers exactly), so you could only rely on the metals delivered in the past few hundred million years. Asteroid impacts are getting rarer all the time, especially big ones.

Also, recall that a given asteroid is as likely as much rock as metal. In fact, Earth is more metal per mass than the average asteroid. (A lot of our silicates ended up in the Moon instead.) However, some asteroids are definitely mostly metallic and for mining purposes, that's a mad bonus. (For metals raining down from heaven, however, you have to factor in the fraction of the asteroids that isn't metal.)

Also, you're not factoring in the costs of bringing metals back to the Earth (if that's your goal). It's far more expensive to do that than to mine them here and will be for the foreseeable future. Of course, if your goal is to use them in space anyway, then it might be better to mine them there. (On the other hand, then you have to build the refining and construction infrastructure in space, which has a lot of challenges of its own.)

Why do you think metals? The best substance you could pull from an asteroid would be ice. Ice can be converted into fuel. Ice can be converted into oxygen. Ice can be converted into water. A good icy asteroid can supply three of the four main consumables of space exploration.

Rare earth metals, the easily mined deposits of which our civilization will probably have depleted in the next 50-100 years. Already there are serious concerns about switching to renewable energy sources based on the low availability of certain key resources.

I think you can go down pretty damn deep before "easily mined" from asteroids becomes more cost effective than "easily mined" here on Earth! You need to mine the asteroids for resources to use in orbit, not to send back to Earth.

Mining stuff here on Earth makes a mess of our environment (more so in some places than others; here in the Arizona desert, it pretty much just results in an ugly pit, but in West Virginia, mountaintop-removal mining causes all kinds of ecological problems).

Now people (like China) are already talking about mining the sea floor, because we've depleted everywhere else. The sea floor is a much harsher environment than space for humans; in space, you just need to design a vessel that can contain a measly 1 atmosphere of pressure. Sending people underwater is much harder since you have to design your craft to keep hundreds or thousands of atmospheres of pressure out. Of course, you can do a lot of work with ROVs, but there's still a lot of technical challenges there because of the depth, and the presence of (very high-pressure) water all around. Space is relatively easy to work in. The only problem is getting out of our gravity well.

Digging deeper into the crust isn't exactly safe, either. Ask the miners in Chile who are still trapped underground.

The ocean floor is a heck of a lot easier to work on and still be home in time for dinner! Remote controlling equipment even in the deepest part of the ocean gives you a lot better ping times then remote controlling equipment in the asteroid belt, i.e. milliseconds versus months of round-trip delay time. The solar system is fucking BIG!

Depends on what you call "home", I suppose... (Seriously: thanks to Time for Timer[1], I used to think that the bacteria in my teeth had briefcases, and had some "home" that they went to, when they weren't busy removing my plaque... Ah, childish notions...)

[1] -- "When my ten-gallon hat is feeling five-gallons flat, I hanker for a hunk of cheese!" I think that did far more than the "Got Milk?" campaign did, especially when they started suing any "Got X?"-alikes.

Not only are you forgetting about cosmic radiation, which is a severe hindrance, you're vastly oversimplifying the problem of the gravity well, since sustaining a human presence on an asteroid would require regular shipments of supplies at exorbitant cost. I'm also curious how you expect the raw materials to make it back down to Earth. Actually refining many of these metals in space would also be a pain in the ass, but landing asteroids wouldn't be very

To be fair, the moons of Mars are really nothing more than small asteroids that have been captured by Mars' gravity so that they orbit it. They're very small and irregularly shaped.

However, it seems to me the easiest target would be an asteroid that's in an Earth-crossing solar orbit, or so other nearby asteroid. You don't have to go all the way to the asteroid belt to find asteroids.

IMO an asteroid mission is far and away the best choice for manned exploration. They have practically nonexistent gravity wells, making exploration relatively cheap, and depending on the target selected, could support making life support volatiles and rocket fuel in-situ. A good-sized nickel-iron NEO, on the other hand, could be an excellent prospecting opportunity -- depending on how big it is, it could supply enough iron to sate Earth's steel demand for a century or more -- or it could be used as a reso

There is no urgency to manned missions. We already mechanize as much mining on Earth as possible, to cut costs which include expensive miners (who get killed, maimed, and expensively buried for month).

If we want to mine space resources, don't bring people, make remote systems so good we won't need humans onsite.

A good-sized nickel-iron NEO, on the other hand, could be an excellent prospecting opportunity -- depending on how big it is, it could supply enough iron to sate Earth's steel demand for a century or more -- or it could be used as a resource cache to bootstrap space-borne manufacturing.

OK, serious question here, because I'm baffled.

How do we return any actual meaningful mass from an asteroid? How do we push it home? What it the source of the push?

For one, how do you get a rocket with "significant mass" anywhere? We have enough difficulty getting modules the size of a family car into space, I dread to think how we would significantly increase that. And if you can move a rocket around which is as massive as the asteroids, surely you will have already solved the problem in some way?

For two, I'm inherently nervous about slinging asteroids at Earth with an intention for them to touch down, or enter a steady orbit. Makes you wonder exactly what the dinosaurs were up to in the weeks preceding their unfortunate incident...

Anonymous reader (probably a PR flack for Science) said: "This type of mission has great potential for positive economic return based on the fact that no effort has to be spent on getting in and out of a distant planet's gravity well."

Let's see, from TFA: "Hopkins said that a basic six-month human mission to an asteroid could return about 100 kilograms of samples collected from different spots on the space rock." OK, so you fly directly to the solid gold asteroid and pick up 100 KG of that. That's 3527 ou

You forge the gold into a landing module and use a mass-accelerate to bring it back to earth. You leave your mining equipment out there to get more precious materials until it stops functioning. Bringing your labor force back to Earth is a mistake; then you have to pay them! Actually, you use robotic miners so you don't have to recover them. Ever heard of Self-replicating machines [wikipedia.org]?

They should visit a number of different types of asteroids and nuke them to see the effect.
Its really important knowing what will and won't work in protecting the planet from an asteroid impact.
We have zero experience in how effective nuclear weapons are in deflecting or distinguishing asteroids.
I don't think we want to be doing this when threatened by a large asteroid collision.

the physics of it don't pan out though. any asteroid large enough to be a significant threat is not something we could damage with current nuclear yields and making larger bombs, while possible, would be more dangerous to have here than the remote chance of an asteroid impact.

we'd be better off investigating other means of modifying an asteroids path such as solar sails, robotic mass drivers, parking a small mass near it for gravitational deflection to name a few.

I'm disappointed it's a negative reaction that actually prompted me to log in for the first time in a over a year, but this story is crazy. The whole idea is crazy. Not because of technological limitations, but because we don't have a prayer of paying for it.

"America is basically like a 7-11 that's about to go under. The shelves are barely stocked, the sign has been broken for months, and nobody really gives a shit because they've been watching the boss raid the cash dra

I'm joking. The real answer is that "America" shouldn't be paying for space exploration, "Earth" should be paying for space exploration. It is only because we have militarized space that every country feels they need their own private space program. Get everybody to work together for a common goal, and nobody else will give a shit about the decline of the American empire, which has already started, by the way. Within the next few decades, China will become the leading economic superpower, then they can foot

If we stopped wasting so much money on foreign wars and bailing out mismanaged companies, we could easily afford it. 50 or 100 billion dollars should be enough to fund this, and that's nothing compared to how much money we've wasted in Iraq.

For example: Mining the asteroids for Unobtanium. To mine the Unobtanium, you need to lift the mining equipment to the asteroid. Bring or get the energy to mine it. Load it and de-orbit it from the Belt to Earth AND THEN STOP IT. You can work some cool tricks (slingshots, balutes, solar sails, whatnot) but the energy remains the same. The amount of energy to get something there and back is IMMENSE. You will NEVER recoup that money spent on energ

Solar energy is cheap in space. You could make a parabolic dish a mile across out of mylar potato chip bags and bendy straws, using the focussed rays to drive a steam driven electric generator. Delta-V is the costly item, and that means propellant, and once you find a big block of ice floating around somewhere, you've got your propellant.

Since real manned exploration of Mars is a pipe dream at this point (both technologically and financially), a manned trip to an asteroid is just the ticket if you want to stay in the manned exploration business. The Moon? Been there done that. Mars? Can't do that yet. Asteroids are do-able, and when it comes to manned exploration, fairly cheap. Unless we're going to abandon manned exploration completely, then an asteroid is the next logical "First" for NASA.

Why manned? Sending robots on a one-way mission is always going to be an order of magnitude cheaper than sending humans and safely bringing them back home. However, sending humans on a one-way mission may be cheaper still!

Why manned? Sending robots on a one-way mission is always going to be an order of magnitude cheaper than sending humans and safely bringing them back home. However, sending humans on a one-way mission may be cheaper still!

I simply don't understand how anyone human can have this attitude. I'm all for doing most exploration via robitic means, but for man never to go to new areas himself? Further, if we don't do it, someone else... China, India, Russia, someone... is going to go. They're certainly not going to ignore the human factor.

Exploration isn't just about science, and never has been. In fact, even with the advent of the scientific revolution, I'd say science has been at best a minor motivation. Simply getting there is pa

Apollo had enough delta-V for a mission to a near earth asteroid, and could have made the duration with a stretched service module for more life support. The design issue is whether to build a big, slow vehicle, or a small, fast vehicle. The slow option gives you more to build on for the future. The fast option has less risk because a quick return to Earth is built in from the start.

Once again, that "return to Earth" is your biggest money waster. One-way trips are an order of magnitude cheaper. Big, slow vehicles with a multitude of redundant robotic self-replicating explorer/miners are the way to go. If they can find enough material to make copies of themselves faster than they break down, than the whole operation is self sustaining. Just don't be surprised in a few thousand years when they evolve to the point where they come back and take over the Earth!

It would work if we were going to commit to a colony somewhere like Titan or Mars, but there would have to be continuous expenditure. An unmanned supply every year and new man power every ten years, perhaps. It would be interesting how many qualified people you would find. You need people who have no interest in having children. who don't want to live on Earth (be able to go for a walk in the bush, etc) and who are not interested in the social aspects of living in a large community.

You need people who have no interest in having children. Or have already had their children, i.e. "old people". You need people who don't see a qualitative difference between living in the Mom's basement downloading porn all day and living in a tin can 100 million miles from home and downloading porn all day. All real work in extreme environments should be done by robots. Very few humans are needed to work around the speed-of-light propagation delays in running everything from back on Earth, i.e. humans are

Apollo was completed in less than ten years. That occurred with very little prior knowledge and the threat of a Russian moon hanging over us. Even with that Congress canceled the last two Apollo missions.

This program is planned to take 50% longer than Apollo building upon what we already know. Frankly, any manned mission scheduled to take longer than Apollo will be canceled before it gets off the ground. Between now and 2025 there will be four presidential elections. That is potentially four wishy-w

Not sure if mining the asteroids will have an economical impact down here on earth. But what should be explored there is what we can do. Can we live there? Can we make self-sustained enough stations with materials found there? What about new ships or propulsing fuel? Good part of the cost and ecological impact of space exploration is actually getting into space, leaving planet gravity well. But if most of the needed resources are already out and we can have enough people there in a semi permanent basis, we can start thinking in more advanced space exploration and colonization, maybe getting cheap enough resources (think for what was used the space station in the movie Moon). Of course that are several practical problems, but could we solve them?

NASA needs high profile missions that inspire awe. They need to build excitement and inspire awe. They need to thrive on whiz-bang technology and showcase what the human spirit is capable of achieving. Those are the fundamentals the space program is built on. For the last twenty years they've sucked at it.

I don't want to pass too much judgement on landing on hunks of rock a couple of AU's away, but it sure doesn't seem too sexy to me. I think most people get excited about other things. Throw some rove

Excuse the vent, but NASA has become lame as hell nowadays. What happened? From the space race in the 60s forward 50 years to now, isn't anyone else disappointed? I'm 31, and I was so excited growing up in the 80s, I couldn't imagine what I was going to see. Now, it seems to have all slowed to a crawl. Sure, Hubble gave us some amazing photos and scientific data, but where have the grand leaps and bounds in technology and sheer drive to explore been? Now, we have Obama hamstringing the space program as well, cancelling programs left and right. 2025? Ill be nearly 50, and I'd bet yet to see a man on Mars. I guess I assumed it would happen in my lifetime, and much earlier, even by 2010 at the rate things seemed to have been advancing. The idea of this is cool and all, but I really hoped we would push the envelope a bit harder, like the good old days. Sorry, I guess I'm just underwhelmed and disappointed.

Nixon wanted to get out of manned spaceflight. Follow-on Apollo's were canceled, the Venus fly-by was canceled (you can see the crew module at the Air and Space Museum, except it's labeled "Skylab"), the Saturn V was thrown away, the Germans and Americans from the 1930's were all retired, from Von Braun on down, the middle-engineering of Apollo was all fired (I remember PhDs pumping gas in Florida), and what was left was the bureaucrats. Bureaucrats can run things, but they won't give you grand leaps.

I remember someone predicting that when Bush announced his planned trips to mars and the moon, it was really a politically astute way of dumping the space program without looking like he was dumping the space program. There was no provision for how to pay for these new missions and by the time actual funding was going to be needed, it would be somebody else's problem (without even having to paint the shuttles pink). Otherwise, the very real problems of what to do with the short term needs at NASA were going to be center stage and have to be dealt with in his administration. The lack of a shuttle replacement, problems with the existing shuttle's safety/reliability, how to maintain the ISS, etc.

You, me, and pretty much every other engineer in existence shares this feeling. At its peak during Apollo NASA funding was 8 times the current $17 billion rate and I think it was worth it. You want more scientists and engineers here in the US, land a man on Mars. By the time we do it, I am pretty sure the world wide audience will be billions of people, easily toping the 15% who watched the Apollo landings.

My opinion is that, as a culture, we've become too risk averse. The requirement to (and expense of) engineering every possible conceivable thing that could go wrong out of, well, everything, is destroying the possibility of achieving anything.

I used to love NASA but these days, I wouldn't bet a nickel that they could make it to the nearest gas station with a GPS, atlas, and police escort to guide them. Honestly, if they were somewhat independent of the political process and could exist as an autonomous institution, they may have a chance. But, there's no way their priorities will remain set for fifteen years when they couldn't even last five years. Hell, I don't think they'll make it the next five years without any public facing launches. Th

This type of mission has great potential for positive economic return... we should master mining the asteroid belt for resources first because it is easiest.

Positive economic return? How much would it cost to go get 1000 tons of, say, bauxite and extract the aluminum? How much would the resulting aluminum cost to produce? Would there be a "positive economic return?" Answer 1) bringing it back to earth, 2) doing it off-planet (you still need to bring back the aluminum, though). Include the cost of buildin

I know this is going to sound like a troll, but what's the point.nasa has become nothing but a pet poodle that each new administration scraps the work of the previous one and wastes all the funding that went into it for some new vision.

I used to love space and nasa, but now days i just get annoyed.

I'm starting to agree with putting space in the private sector but not for the reasons the current admin' says.i want space exploration out of the hands of the politicians.

My view of the initial space race was that it was more of a political statement of "look how advanced we are! we can fly to the moon!" disguised as science. Sure it was exciting, but the real gain was in politics. Today, its just doesnt carry the political "wow" factor. Who cares when the average small country has the bomb. Robots were always better than sending people anyhow. As for mining, there are mines on the earth that are much more profitable to mine. You think we have issues with some miners do

One advantage to being on, or in "orbit" around an asteroid or other small body (like the moons of mars), is that it is relatively quick and easy to change and hold one's position relative to that body. So if the astronauts see a solar flare coming they just move into the shadow and hang out there for the few hours it takes for it to pass. No expensive delta-v, no digging in the dirt.

Of course Arthur C. Clarke foresaw this in his story about a visit to the asteroid Icarus.

I think the mining idea misses the point. This NASA plan is all about gaining experience surviving outside of low earth orbit.

1: Surviving without the massive radiation shield that earth's magnetosphere provides.2: Surviving without an option for quick Earth return.3: Surviving without near instantaneous communication with ground control, Major Tom.4: Surviving extended exposure to zero-g (muscle and bone loss)

Well #4 has already been worked out a lot at ISS though the amount of exercise needed is significant (less mission time) and not perfect (still need to get strong again when back on earth).Shall we start debating the need for artificial G via rotation?

Also #2 has been somewhat worked over with ISS, specifically the need for lot's of spare parts, redundant systems, and design for easy repair. What's not so well covered is, wetware repair. MedBay anyone? Is there a doctor in the house?

A very long time ago, in a galaxy far, far away (MIT, mid 1970's, when I was an undergraduate and a member of MIT"s Planetary Astronomy Laboratory of that era), I remember having conversations with Mike Gaffey about asteroid mining. I see a reference to Technology Review on asteroid mining from Mike in 1977, so I think this got all published; I don't have any TR's of that era around to refresh my memory.

I remember one interesting scheme, where you might take a m-type metallic asteroid (which is mostly iron, nickel, and other useful metals) to earth orbit, by any of a number of propulsion schemes (solar sail, ion engine, or the like). It would probably take a number of years to move it from the asteroid belt to earth orbit. Then foam the asteroid (use solar mirrors to make it molten, and inject gas), and shape it into a lifting body. Then you would fly it into the earth's atmosphere, and land it in the ocean outside any port you would care to deliver it to. The point of foaming it was to reduce its density so that it would reenter the earth's atmosphere without much heating and ablation (we don't want to dump lots of metal into the earth's upper atmosphere), and float when you landed it.

Then you take a tug boat and pull it to a dock, and you have however many kilotons of metal you like. And without the huge energy cost of mining and environmental problems on earth.

As I remember, all the physics work (without having to invent fundamental new technologies), and there are lots of metallic asteroids. Now we just have to figure out how to actually do it. And it is way, way easier to deal with getting to and from the asteroids than the moon or any planet.
- Jim

This type of mission has great potential for positive economic return based on the fact that no effort has to be spent on getting in and out of a distant planet's gravity well.

Someone is forgetting that one has to get in/out of EARTH's gravity well which is the biggest one outside of the gas giants. Then you have to actually mine whatever it is (which we lack the technology to do) in deep space and safely bring it back intact. What are you going to mine in any serious quantity that you can safely return to earth without the item either burning up in the atmosphere or turning the item being returned into a weapon. (Remember that any significant fraction of an asteroid makes a heck of a divot when it hits the earth at high speed.) I can't imaging there are a lot of asteroids composed of precious metals floating around. Maybe there is an asteroid filled with inkjet refills or human blood?

Seriously, even ignoring the technical issues (which are huge) I haven't heard anything relating to mining asteroids that remotely makes economic sense. What could we possibly mine on an asteroid that could be worth the enormous cost of retrieving it from the asteroid belt? We only have a vague idea of what many of these things are composed of and what we do know isn't anything terribly rare here on Earth. The idea of mining asteroids is a romantic and cool idea but we would have to be SERIOUSLY in desperate need of something to make the economics of asteroid mining make any kind of sense.

Ok, the real deal here is manufacturing facilities, not mining per se. There are TONS of asteroids all over the moon, that could be used for early mining to support manufacturing on the moon.

And really the best way to "mine" the asteroid belt as one said in reference to hauling stuff, would be fishing for stones, and then hauling them back to the moon. Thrown down where it would be safe enough, but far enough from the manufacturing facility, and then hauled mined and manufactured back there.

THis would of course be multiphase and requires just tons of energy. Nuclear batteries are not likely to create enough energy, and other forms of nuclear energy require ALOT of water. So we have a basic problem in creating MINING and MANUFACTURING levels of energy. Energy to create steel for instance. Without water or internal combustion engines, it becomes tough to make that amount of energy.

The asteroid mission is mandated to use nuclear power to travel in space (not launch). I like nuclear power, but there are some hard technical leaps to get through for that to be a viable propulsion source. Granted, it's more likely to work than getting a usable electric powered car in the US, but the odd combination of setting a destination objective (e.g. asteroids) with a mandatory technology (e.g. must run on cheese) shows novice planning work.

What was cancelled to make room for the asteroid mission was the Mars mission. Why? Well, the administration says that the asteroids are closer. I Am Not a Scientist (IANAS), but through careful and methodical research I've determined that the moon is still closer. And it likely has minerals, has some gravity to help with biological issues like muscle atrophy, etc. Oh, and we've already gone there with 1960's technology, so it's a pretty close bet we could do it again.

The current big problem is getting mass to (or out of) orbit. If you want to pretend the government's best role is things like infrastructure, they should fund private companies to develop heavy rockets for lift, space factories for building space-launched rockets, or a space habitat that isn't in low Earth orbit.

My suspicion is the asteroid mission was selected because failure (or future cancellation) will be hardly noticed. However, everyone would certainly notice a habitat on Mars or the moon that we no longer use. The saying goes "If we can send a man to the moon" not "If we can rendezvous with an asteroid!"

Finally, there are no intermediate goals in the strategy. Just "get there." What we don't need is NASA to wander about for years developing "stuff" with no progress. We've already seen that for too many decades.

There are a lot of near-Earth asteroid, like Toutitis a few years ago. Send a mission to one, and alter its orbit so that it enters near-Earth orbit, say at geosync. Then we'd have a *real* space station, once we dug into it, and used it for raw materials, one that would have real protection against solar flares, and that could be used to base true deep-space ships (that only go from orbit to orbit) to the Moon, Mars and beyond. This would make interplanetary travel for humans far cheaper.

For that matter, we could use nuclear (steam) rockets from there, which would make trips a lot faster.

Picture the old grizzled prospector and his faithful burro, quickly asphyxiating due to lack of oxygen! It's a lot easier to get air and climate control into even a 10-mile deep hole in the ground than it is to get it out to the asteroid belt.

As the remains of planetary building blocks, the asteroids may contain an incredible wealth of minerals, easily accessible compared to other planetary bodies, and easily evaluated. Picture gold nuggets in space.

Operative word: "may"

I however, doubt that asteroids contain an "incredible wealth of minerals. Useful mineral deposits on earth are formed from heating and pressure. It's unclear that asteroids are / were subject to these forces. It may just be a bunch of low grade rock.

First we have to ask ourselves, how many people can our planet sustain? 10 billion? 15 billion?

Realize that if the idiots have their way the right answer is 250 million. If you want to lock down the Earth and treat it as a closed system, this is probably a reasonable limit.

The first step is to make sure the idiots do not succeed. Probably part A of that plan is making sure that space exploration isn't pushed aside for "solving Earthbound problems first" because that is the same as "never".

NASA can have all the plans they want, but the current administration seems to be focused on cutting them off a

How about we work on figuring out a way to stop reproducing like rabbits. Until we have a world wide control on population levels we are doomed to continuously suffer from famines and poverty on ever larger scales. The whole idea of terraforming Mars is a pipe dream due to the lack of a magnetic field to provide protection from the Sun. Mars may have been wet at some point but its core cooled down to quickly and lost its magnetosphere and most of It's atmosphere. Until we can produce a Warp drive or build

If you think we've got population problems you clearly haven't been paying attention. East Asia, which has some of the highest population densities in the world also has among the lowest birth rates. The rate for China is lower than the US. Nations like Japan, South Korea and Taiwan have among the lowest rates in the world. Most of Europe also has extremely low birth rates. If it weren't for immigration America's rate would probably be a lot lower than it is. I don't know if Europe still does it, but Japan